Transplanting a tendon for replacing a ruptured ligament by surgery is one of the conventional methods for curing a broken ligament due to an injury or damage caused by an accident.
Especially, an anterior cruciate ligament (hereinafter referred to as “ACL”) rupture which frequently occurs in professional sports such as in baseball and soccer, also occurs at a high frequency among general public during exercise and due to accidents. The number of ruptures per year reported in Japan has been 20,000 to 30,000, and 100,000 in the United States. 15,000 cases in Japan and 50,000 to 75,000 cases in the United States received treatments using the aforementioned reconstructing method.
Options for obtaining tendons for the abovementioned method for ligament curing are autograft transplantation using autogeneous tendons, which is predominantly performed; allograft transplantation using allogeneous tendons including tendons from dead body; and artificial graft reconstruction.
In an autograft transplantation, transplant-use tendons are usually supplied from one of the patellar ligament (a tendon at the front side of patella), the semitendinosus ligament (and gracilis ligament), iliotibial band (a ligament at the side of thigh) and the quadriceps femoris tendon. In many cases, the patellar ligament or semitendinosus tendon (and gracilis tendon) is used.
The supplied ligaments described above are used for surgical reconstruction of a ruptured ACL. In the single-socket method, for example, a tunnel is formed from the lower part of the femur to the upper part of the cnemis, through which a ligament is directed to be used as a replacement of ACL.
Using the abovementioned single-socket method, there are two types of surgical procedures to perform an autograft tendon reconstruction. One method uses a patellar ligament, more specifically, a tendon under the patella is taken out and transplanted to the position of the ACL (hereinafter referred to as the “BTB method”). Another method uses a semitendinosus tendon, to be more precise, a string-shaped tendon located at rearward of inner side of knee is taken out and folded four times in order to increase its thickness, and this tendon is transplanted to the position of ACL (hereinafter referred to as the “ST method”).
However, the BTB method has problems as follows:
(1) Pain may remain after surgery in the front side of the knee from which tendons and bones are taken out. (This is especially common in women.)
(2) Post-surgical algia/pain is more severe than when other methods are performed.
(3) Knee extension strength (kicking force) is weakened.
(4) The reconstructed tendon becomes flat.
In contrast, the ST method has several advantages as follows:
(1) There are two options, a “single-route practice” in which a single thick tendon is reconstructed, and a “double-route practice” in which two tendons are reconstructed.
(2) Post surgical pain is less at the site where the tendon is taken out.
(3) Surgical scarring is extremely small.
(4) Decrease in muscle strength after surgery is small.
For this reason, the instant inventor who engages in medicine has been performing surgeries in which semitendinosus tendons (and gracilis tendons) are taken out and transplanted. However, because such tendons are very long and thin, it is difficult to remove them.